mm: make CONFIG_MIGRATION available w/o CONFIG_NUMA
We'd like to support CONFIG_MEMORY_HOTREMOVE on s390, which depends on
CONFIG_MIGRATION. So far, CONFIG_MIGRATION is only available with NUMA
support.
This patch makes CONFIG_MIGRATION selectable for architectures that define
ARCH_ENABLE_MEMORY_HOTREMOVE. When MIGRATION is enabled w/o NUMA, the
kernel won't compile because migrate_vmas() does not know about
vm_ops->migrate() and vma_migratable() does not know about policy_zone.
To fix this, those two functions can be restricted to '#ifdef CONFIG_NUMA'
because they are not being used w/o NUMA. vma_migratable() is moved over
from migrate.h to mempolicy.h.
[kosaki.motohiro@jp.fujitsu.com: build fix]
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: KOSAKI Motorhiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 3a39570..085c903 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -59,6 +59,7 @@
#include <linux/rbtree.h>
#include <linux/spinlock.h>
#include <linux/nodemask.h>
+#include <linux/pagemap.h>
struct mm_struct;
@@ -220,6 +221,24 @@
extern int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol,
int no_context);
#endif
+
+/* Check if a vma is migratable */
+static inline int vma_migratable(struct vm_area_struct *vma)
+{
+ if (vma->vm_flags & (VM_IO|VM_HUGETLB|VM_PFNMAP|VM_RESERVED))
+ return 0;
+ /*
+ * Migration allocates pages in the highest zone. If we cannot
+ * do so then migration (at least from node to node) is not
+ * possible.
+ */
+ if (vma->vm_file &&
+ gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
+ < policy_zone)
+ return 0;
+ return 1;
+}
+
#else
struct mempolicy {};
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index e10a90a..03aea61 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -3,28 +3,10 @@
#include <linux/mm.h>
#include <linux/mempolicy.h>
-#include <linux/pagemap.h>
typedef struct page *new_page_t(struct page *, unsigned long private, int **);
#ifdef CONFIG_MIGRATION
-/* Check if a vma is migratable */
-static inline int vma_migratable(struct vm_area_struct *vma)
-{
- if (vma->vm_flags & (VM_IO|VM_HUGETLB|VM_PFNMAP|VM_RESERVED))
- return 0;
- /*
- * Migration allocates pages in the highest zone. If we cannot
- * do so then migration (at least from node to node) is not
- * possible.
- */
- if (vma->vm_file &&
- gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
- < policy_zone)
- return 0;
- return 1;
-}
-
extern int isolate_lru_page(struct page *p, struct list_head *pagelist);
extern int putback_lru_pages(struct list_head *l);
extern int migrate_page(struct address_space *,
@@ -39,9 +21,6 @@
const nodemask_t *from, const nodemask_t *to,
unsigned long flags);
#else
-static inline int vma_migratable(struct vm_area_struct *vma)
- { return 0; }
-
static inline int isolate_lru_page(struct page *p, struct list_head *list)
{ return -ENOSYS; }
static inline int putback_lru_pages(struct list_head *l) { return 0; }
diff --git a/mm/Kconfig b/mm/Kconfig
index c4de852..aa79900 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -174,7 +174,7 @@
config MIGRATION
bool "Page migration"
def_bool y
- depends on NUMA
+ depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE
help
Allows the migration of the physical location of pages of processes
while the virtual addresses are not changed. This is useful for
diff --git a/mm/migrate.c b/mm/migrate.c
index e7d13a7..376cceb 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1071,7 +1071,6 @@
mmput(mm);
return err;
}
-#endif
/*
* Call migration functions in the vma_ops that may prepare
@@ -1093,3 +1092,4 @@
}
return err;
}
+#endif
